Method for chilling poultry

ABSTRACT

Eviscerated poultry is conveyed upon a shackle through a refrigerated space in a compact configuration for a time sufficient to chill birds so as to cause them to self-retain the compact configuration when delivered to a bird packaging station for packing in the same configuration. The shackle itself has a basket pivotably mounted to a lower portion of a hanger bar and a canopy mounted to an upper portion of the bar.

This is a divisional of co-pending application Ser. No. 477,269, filed on Mar. 21, 1983, now U.S. Pat. No. 4,513,476.

TECHNICAL FIELD

This invention relates generally to methods and apparatuses for processing poultry, and particularly to methods and apparatuses for chilling birds such as young broilers preparatory to packaging as fresh poultry.

BACKGROUND OF THE INVENTION

In poultry processing plants today, where poultry is prepared for sale as fresh produce, birds are killed, eviscerated and chilled prior to being bagged for distribution and sale. The birds are chilled to enhance moisture retention so that they will stay moist when cooked and so that the skin will not tend to separate from the meat for enhanced eatability and cosmetic appearance. The chilling is typically done by dropping eviscerated birds into a tank of cold water for a period of time sufficient to lower the body temperature from some 90° to 98° F. following evisceration, to some 35° to 40° F., depending on their size.

More recently, birds have been chilled to a much lower body temperature, just above their freezing temperature, for the same reasons, i.e. for better moisture retention and skin adherence as well as for improved coloration and shelf life. This has been done by what is known as a crystal pack operation wherein birds are passed through a refrigerated room suspended from shackles following their emergence from the chiller. Within the crystal pack room the birds are subjected to a flow of cold air being blown at high velocities for a period of almost an hour. This operation serves to lower the body temperature of the bird from some 35° to 40° F. following emergence from the chiller to approximately 29° F. with the skin of the bird being approximately at 281/2° F. At this temperature the birds are very close to but are not actually frozen although moisture on the skin of the bird will have crystallized. As previously stated, this crystal pack operation serves to enhance shelf life of the birds and also to enhance the birds cosmetically. Particularly, this form of chilling renders the bird more yellowish due to the fast rate of heat removal. Again, better moisture retention is also achieved as is skin to meat adherence.

Though the just described crystal pack operation has provided the just described advantages it is not done so without creating certain disadvantages of its own. Probably the most important disadvantage associated with crystal pack operations has to do with the difficulty of modeling or shaping the birds for insertion into a packaging bag for shipment and distribution. Prior to the use of the crystal pack operation the termperature of the birds was only reduced to some 35° to 40° F. At this temperature the birds, which are typically young broilers of some seven to eight weeks of age, are sill sufficiently pliable or flexible so as to enable workers to form or truss them into a compacted configuration which sometimes in the industry is referred to as a "butterball" shape. In this configuration the thighs of the birds are raised up against the bird breast with wings usually tucked in between the thighs. With the use of the crystal pack operation, however, the temperature of the birds has been reduced over a substantial period of time almost to a body frozen temperature prior to bagging. This causes the birds to be stiff due to their cold body temperature and the effects of rigor mortis. It thus is difficult to shape or model the birds into the compact, butterball position during the packaging operation. This is particularly true in view of the fact that the birds are suspended invertedly from shackles in a stretched-out position as they are conveyed through the crystal pack room. This stretched out position is, of course, just the opposite of the compacted, butterball position. In addition, in the invertedly suspended position the birds take different orientations such, for example, with one or both wings draped downwardly or at some inclined angle. This leads to variations in time required to bag the birds which are being delivered to the packaging station at regular intervals. The inverted conveying position also leads to weepage during crystal pack operation wherein moisture may be lost from the surface of the skin.

Accordingly, it is seen that a need remains for overcoming the just described problems associated with the use of crystal pack operations in the processing of poultry for sale as fresh produce. It is to the provision of a solution to the just described problem that the present invention is primarily directed.

SUMMARY OF THE INVENTION

In one form of the invention a method of processing poultry comprises the steps of mounting a bird upon a shackle modeled such that the shackle holds the bird in a trussed position with the wings tucked in between the thighs and the thighs pressed against the breast. The bird is conveyed through a refrigerated space for a period of time sufficient to chill the brid so as to cause it to self-retain the trussed position. The birds are then dismounted from the shackle and bagged while still sufficiently chilled to retain substantially the trussed position.

In another form of the invention a method of chilling poultry preparatory to packaging as fresh produce comprises the steps of mounting a bird in a compact position to a shackle of the type having a basket and a canopy located above the basket with the breast supported in the basket, the thighs pressed against the breast, the hocks held in by the canopy and the wings tucked in between the thighs. The bird is conveyed while mounted in the compacted position to the shackle through a refrigerated space for a period of time sufficient to chill the bird so as to cause it to self-retain the compacted position at least briefly when dismounted from the shackle whereby it may then be packaged in the compact position.

In another form of the invention a shackle for conveying poultry in a compact configuration comprises an upright hanger bar, a basket pivotably mounted to a lower portion of the hanger bar for movement between a generally horizontal, bird supporting, raised position and a generally vertical, bird dumping, lowered positon. The shackle has a canopy mounted to an upper portion of the hanger bar above the basket for holding an upper end of a bird supported on the basket, and latch means for releaseably holding the basket in the raised position.

In still another form of the invention a shackle for conveying poultry comprises an upright hanger bar, a swing arm pivotably mounted to a lower end of the hanger bar and having a step formed in its upper surface so as to define a catch, and a basket mounted to the swing arm. The shackle also has a latch bar positioned aside the hanger bar supported upon the swing arm upper surface for movement into and out of engagement with the catch upon pivotable movements of the swing arm, and means for guiding movement of the latch aside the hanger bar.

In yet another form of the invention apparatus for supporting, conveying and discharging a bird in a trussed configuration comprises a hanger bar, a lower support upon which the bird breast may be cradled pivotably mounted to a lower portion of the hanger bar for movement between a bird supporting position and a bird discharging position, and an upper support mounted to an upper portion of the hanger bar spaced from the lower support a distance such as to retain the hocks of a bird supported upon the support in the bird supporting position but too great a distance to retain the hocks of the bird supported upon the lower support in the bird discharging position. The apparatus also has means for releaseably latching the lower support so as to hold the lower support in the bird supporting position.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective view of a shackle embodying principles of the present invention;

FIG. 2 is a front view of the shackle shown in FIG. 1 loaded with two birds;

FIG. 3 is a side view of the loaded shackle shown in FIG. 2;

FIG. 4 is an unloaded side view of the shackle shown in FIG. 1 illustrated in a bird discharge position; and

FIG. 5 is a schematic illustration of a poultry processing line that extends through a chill pack room.

DETAILED DESCRIPTION

With reference to the drawing there is shown in FIG. 1 a shackle 10 having an upright hanger bar 12. The top of the hanger bar is formed with a pair of holes 13 so that it may be secured by bolts to a conveyer line carriage while the bottom of the bar is formed with a fork 14. A swing arm 15 is pivotably mounted to the hanger bar fork 14 by a bolt 17. A stop pin 18 is mounted to a swing arm to limit its pivotable movement to that position shown in FIG. 4 where it contacts the hanger bar fork. A counterweight 19 is secured to, or formed unitarily with, the swing arm to cause the swing arm to assume the horizontal position shown in FIGS. 1-3 when the shackle is unloaded. Two baskets 20 are mounted to the swing arm with one basket extending laterally to one side of the arm and the other extending laterally to the other side.

A canopy 23 is mounted to the hanger bar 12 spaced from the baskets 20 a distance such as to support the hocks of poultry being invertedly supported in the baskets. This distance will, of course, depend on the type and size of the birds being processed. The canopy includes an inverted L-shaped plate 24 to which a U-shaped bar 25 is seucred as by welding.

Finally, a latch bar 28 is loosely mounted aside the hanger by means of two half-rings 29 and 30 secured to the hanger bar through which the latch bar passes and another half-ring 13 secured to the latch bar through which the hanger bar passes. An upper portion of the latch bar is formed with a lift arm 33 while the lower end is formed with a tongue 34. This tongue slidably rest upon an edge of the swing arm 15 for seating engagement in a catch 36 provided by a notch in the edge of the swing arm.

In operation two birds are loaded upon a shackle at a loading station 40, as shown in FIG. 5, in an inverted compacted, butterball shape as shown in FIGS. 2 and 3 with the breasts resting in the shackle baskets 20 and the hocks held within the confines of the canopy 23. The loaded shackle is then conveyed by conveyer 42 into a crystal pack room 44 in which air is circulated at a temperature of some 0° F. The shackle and birds are moved along a serpentine route in the crystal pack room for approximately 55 minutes whereupon the body of the birds reach a temperaturea of approxmately 29° F., where the birds are eight-week old broilers, and the skin a temperature of about 281/2° F. The shackle and birds then emerge from the crystal pack room and are conveyed to a packing station 45 where they are discharged. Here, discharge is automatically effected by lift arm 33 engaging a cam bar which causes the latch bar to rise along side of the hanger bar thereby bringing tongue 34 out of catch 36. When this occurs the swing arm rotates, under the weight of the brids, to the vertical, discharge position shown in FIG. 4 and the birds fall from the baskets 20. To insure that they do fall free, and are not held to the baskets as by frozen adherence, rotating paddles may be also employed to knock the birds free. Once the birds have fallen from the shackle the baskets are automatically raised by the counterweight 19, the latch bar dropped into the catch by disengagement from the cam bar, and the unloaded shackles conveyed to the loading station 40.

When the birds are discharged from the shackle and conveyer at the pack station, they are in the butterball shape. A worker may therefore easily bag them in this same configuration for sale at retail. And since they have been in this shape during their transit through the crystal pack room they have not been subjected to substantial weepage.

It should be understood that the just described embodiment merely illustrates principles of the invention in one preferred form. Many modifications, additions and deletions may, or course, be made thereto without departure from the spirit and scope of the invention as set forth in the following claims. 

What is claimed is:
 1. A method of chilling poultry preparatory to packaging as fresh produce comprising the steps of:(a) mounting a bird in an inverted compacted, trussed position in a shackle having a basket and a canopy located above the basket with the breast resting and supported in the basket, the thighs pressed against the breast, the hocks held in by the canopy and the wings tucked in between the thighs; and (b) conveying the bird while mounted in the compacted position in the shackle through a refrigerated space for a period of time sufficient to chill the bird so as to cause it to self-retain the compacted position at least briefly when dismounted from the shackle whereby it may then be packaged in the compact position.
 2. The method of chilling poultry of claim 1 wherein step (b) the bird is conveyed through a spaced refrigerated to cooler than 10° F.
 3. The method of claim 2 wherein step (b) the bird is conveyed through the refrigerated space for at least fifty-five minutes.
 4. The method of claim 1 wherein step (b) the bird is chilled such that the thigh muscle is at an average temperature less than 30° F.
 5. The method of claim 1 further comprising the step of:(c) conveying the bird out of the refrigerated space to a dismounting station that is at a temperature substantially above that of the refigerated space; and (d) dismounting the bird from the shackle at the dismounting station.
 6. The method of claim 5 wherein in step (d) a portion of the shackle supporting the breast is reoriented with respect to a portion of the shackle holding the hocks so as to enable the bird to fall from the shackle.
 7. The method of processing poultry of claim 6 wherein following shackle reorientation the bird is struck so as to jar loose any skin adhering to the shackle.
 8. The method of claim 5 wherein step (d) the bird is dismounted by pivoting the basket away from the canopy thereby enabling the bird to gravitate out of the shackle.
 9. The method of claim 1, further comprising the step of packaging the bird while still substantially retaining its compact, trussed position. 